This invention relates to an improved quick coupling ball-and-socket joint for pipes, in particular for pipes operating at higher than 5 atm pressure and of more than 100 mm diameter.
For connecting two pipes together, quick coupling ball-and-socket joints have been known for many years, comprising two components to be coupled together, namely a male component and a female component joined to the respective pipes, plus a third component for quickly coupling the first two components together.
The first two components are each in the shape of a bulging tube piece forming a segment of a spherical surface, and are coupled together in mutual contact with incident axes such as to enable a small angle to be formed between the axes of the two pipes.
Said third component, shown in frontal view in the accompanying FIG. 1 and FIG. 2, comprises an annular element 1N which embraces and engages the male component in a transverse plane, and at least two (usually only two) coupling means 2N and 2xe2x80x2N to be hooked to the female component
Each coupling means 2N, 2xe2x80x2N comprises two parallel hooking arms 3N in the form of plates, lying in planes parallel to the axial plane P passing through the longitudinal centre line of the coupling means, and joined together by a transverse front plate 4N fixed to a first end of the arms 3N for its hooking to the female component.
The third component also comprises a pair of flanges 5N for each coupling means 2N, 2xe2x80x2N, in the form of plates fixed rigidly (by welding) to the annular element 1N and lying in planes parallel to the planes of the hooking arms 3N. Each of these pairs of flanges 5N carries a transverse pin 6N for securing the hooking arms 3N in the axial direction.
With at least one (usually only one) of the two coupling means, that indicated by 2N, there is associated a lever means 7N able to move the coupling means 2N in an axial direction to apply axial traction to the coupling means and hence firmly join the male and female components together. The lever means 7N comprises a pair of lever arms 8N in the form of plates lying in planes parallel to the planes of the flanges 5N and hinged at one end to the transverse pin 6N carried by the flanges 5N. The pair of lever arms 8N carries a second transverse pin 9N, parallel to and positioned at a distance from the first pin 6N, and on which the second ends of the hooking arms 3N of the coupling means 2N are hinged.
A characteristic which is of importance to the present invention is that the pair of flanges 5N in both the coupling means 2N and 2xe2x80x2N is positioned on the inside of the pair of hooking arms 3N. In this respect, in the coupling means 2N, both the hooking arms 3N and the lever arms 8N are positioned on the outside of the flanges 5N.
An object of this invention is to improve the described quick coupling ball-and-socket joint, and in particular its third component, in order to achieve a structure able to better support the pressure, especially if relatively high, to which the pipe is subjected.
This and further objects are attained by the invention as characterised in the claims.
The invention is based on the surprising observation that by applying said flanges of the coupling means on the outside of the outer faces of the longitudinal lever arms, considerable advantages are obtained in that the resultant structure is both less deformable and less tensioned than the corresponding traditional structure, with the practical consequence that the third component is able to work at considerably higher operating pressures for equal weight of the joint.